xfs_fsb_to_db
p->bmv_block = xfs_fsb_to_db(ip, got->br_startblock);
xfs_fsb_to_db(ip, start_fsb),
xfs_daddr_t xfs_fsb_to_db(struct xfs_inode *ip, xfs_fsblock_t fsb);
xfs_daddr_t daddr = xfs_fsb_to_db(ip, imap->br_startblock);